While kayaking in the sea, Yume, Rola, and Koharu get lost in a fog storm and end up on a remote island, where they come across Ichigo Hoshimiya. Ichigo explains that she and her fellow Soleil members, Aoi Kiriya and Ran Shibuki, are competing in an island survival contest against rival group TriStar, formed of Mizuki Kanzaki, Yurika Toudou, and Kaede Ichinose. Getting roped into the contest too, Yume and Koharu end up joining Soleil's team while Rola joins TriStar's team, learning all about each other. After spending the day building a boat for a race taking place the next day, the girls set up a campfire and enjoy a sushi dinner. The next day, Yurika's pet bat Alan goes missing, but Ichigo and Yume manage to find him, enjoying a mountain climb in the process. After Soleil manage to win the boat race, they reveal themselves to be idols from Starlight Academy who put on a show.